pilates or yoga?
 

My mom asked me the other day which should she try to add to her exercise program to lose weight. She has lost but is still a bit heavy. I said pilates instead of yoga. Yet, which is better. She really does not weight lifting so I thought pilates would give her more benefits. My other question is what Video is best for each. She needs something difficult but that isn't crazy. She already does some of the basic exercises pretty easy that we've seen on yoga and pilates basic exercise videos.

I don't see yoga and Pilates as an either/or question. There are some similarities, but the goals and focus are really different. For a pure "workout" Pilates would probably be best, while yoga is more of a whole-body-and-mind discipline. You might want to take a look at this article by Kathy Smith which explains the differences: http://diet.ivillage.com/workouts/0,,h3bz,00.html

As for videos, I really recommend the Gaiam "Yoga for Weight Loss" and "Pilates for Weight Loss" series. The "for weight loss" doesn't mean they are extraordinarily calorie-burning or anything, but that they are made with overweight people in mind, and offer modifications of most moves -- if you can't do it the classic way, they offer easier ways to get the same effect until you can work up to the more difficult move. If you get the DVD rather than the tape, you can actually choose which version to watch throughout the session.